Courtesy of Tim R.:
Basically, this video utilizes the concept of pressure and vacuums to accelerate a ping pong ball to supersonic speeds, enough to send it straight through a paddle. Teh pinp pong ball is placed inside a vacuum tube, and pressurized air is shot extremely fast through it, pushing the ball at very high speeds, somewhere around Mach l.23, I believe. The actual event happens at around 5:48, with the time before it being explanation of the concepts. I thought it was pretty cool, so I hope I gave you everything you need to put it on the class blog.